Composition for scouring natural silk and textile fibres

ABSTRACT

A COMPOSITION FOR SCOURING TEXTILE FIBRES, CHIEFLY NATURAL SILK, MORE PARTICULARLY FOR SIMULTANEOUSLY SCOURING AND DYEING THE SILK, THE COMPONENTS OF THE COMPOSITION BEING MAINLY ABOUT 50 PARTS BY WEIGH OF SODIUM OLEATE, ABOUT 35 PARTS OF AN ALKALINE PRODUCT AND ABOUT 15 PARTS OF SODIUM HEXAMETAPHOSPHATE.

R. MACHON ETAL 3,664,805

COMPOSITION FOR SCOURING NATURAL SILK AND TEXTILE FIBRES May 23, 1972 Filed Jan. 15, 1970 TIME 40' so United States Patent US. Cl. 8-138 4 Claims ABSTRACT OF THE DISCLOSURE A composition for scouring textile fibres, chiefly natural silk, more particularly for simultaneously scouring and dyeing the silk, the components of the composition being mainly about 50 parts by weight of sodium oleate, about 35 parts of an alkaline product and about 15 parts of sodium hexametaphosphate.

Our invention has for its object a novel composition for scouring natural silk and textile fibres within the scope of the technique relating to the treatment of textile material.

Our novel composition is applicable inter alia in the execution of the method for simultaneously scouring and dyeing natural silk in accordance with the teachings of our copending application, S.N. 873,857 filed Nov. 4, 1969.

Further applications of our novel composition are to be found in the technique relating to the scouring of various textile fibres.

The interest of the product, chiefly in the case of silk scouring will be readily understood upon consideration of the research work made on the distribution of sericine and fibroin in natural silk, which work has shown that the fibroin as illustrated at F in FIG. 1 of the accompanying drawings forms the core of the silk thread and is surrounded by three layers of sericine as shown at A, B, C.

The chemical composition of the outer sericine layers is different from that of sericine and its centestimal formula is C H N O whereas the centesimal formula of the composition of fibroin which is different, but very similar, IS C15H23N5O5.

The molecular groups forming the inner sericine layer C are intimately associated with the fibroin groups during the secretion of the silk by the silk Worm Bombyx Mari. The paste thus obtained which does not as yet form a. thread receives in succession the sericine layers B and A. The globular structure of the layers A and B is highly sensitive to the action of hot alkaline solutions whereas the macromolecular structure of the fibroin protects the latter against such an action provided the pH of the solution is not too high, which would lead to a destruction of the fibroin.

It is therefore important to find some intermediate means so as not to act on the layer C at least to any substantial extent and to exert no action at all on the fibroin whereby a protecting layer is retained for the latter, the brilliancy and yieldingness of which are thus unimpaired.

Our'improved novel composition allows this result to be obtained. Said composition is adapted furthermore to remove the greasing oils and impurities carried by all natural, vegetable or synthetic fibres.

Said composition incorporates according to our invention a large percentage of sodium oleate, whether pulverulent, granular in admixture with other components or otherwise.

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An auxiliary feature of our invention consists in incorporating with said component in addition to the sodium oleate sodium hexametaphosphate together with sodium carbonate and/or possibly sodium phosphate or the like alkaline products.

According to a particular embodiment, the percentages by weight of the components of our composition may be as follows:

50% of sodium oleate 35% of sodium carbonate or phosphate or the like alkaline product 15% of sodium hexametaphosphate Further features and advantages of our invention will appear from a reading of the following disclosure, reference being made to the accompanying drawings wherein:

FIG. 1 already referred to is, on a considerably enlarged scale, a cross-section of a thread of natural silk showing the layers of sericine enclosing the inner fibroin.

FIG. 2 is a chart illustrating the modifications in the pH during a treatment resorting to our improved composition for the simultaneous scouring and dyeing procedure according to our prior above-mentioned application.

Our novel composition is constituted by the abovementioned components the percentages by weight of which are substantially those defined hereinabove, said components being commonly sold in trade, generally in a pulverulent or granular condition.

Said composition is prepared in one or more vats, preferably of stainless steel so as to prevent corrosion, a mixer provided with stirring means and a crusher.

The first step consists in crushing carefully and separately the sodium carbonate or the like alkaline product and the sodium hexametaphosphate so as to cut out agglomerates.

A suitable amount of sodium oleate is then poured into the mixer which is provided with energetic stirring means after which the crushed sodium carbonate and hexametaphosphate are poured into the mixer in bulk in any desired sequence.

The three components are mixed together very intimately in the mixer which is provided for this purpose with a cover so as to prevent any scattering and volatilisatio'nof the components.

The time required for mixing purposes may vary according to the amounts to be mixed and also to the rotary speed of the mixer without any definite value being prescribed.

For instance and by way of example, in the case of 10 kg. of the mixture filling a stationary vat provided with a stirrer revolving at 1,370 r.p.m., 10 min. are required for obtaining the final product ready for use.

Said product may serve advantageously in the execution of the simultaneous scouring and dyeing method accordilng to our prior above-mentioned application. In such a case, the treating bath should contain 5 to 6% by weight of the product constituted in accordance with our present invention, with reference to the weight of the silk to be treated in accordance with our said prior application.

The chart of FIG. 2 illustrates the modifications in the pI-Iwhen our novel composition is used. In said chart, the values of the pH are given out as ordinates and the durations of treatment as abscissae. The value of the pH at the start is raised by the alkaline nature of the composition according to the present invention, which ensures regularity in the progression of the treatment as shown by the graph. Of course, as disclosed in our said prior copending application, a sudden large drop in the pH value is obtained at a predetermined moment so as to stop the scouring operation.

The level portions of the graph in FIG. 2 show that our novel composition stabilizes the execution of the method disclosed in our prior application and shows furthermore the advantage of entirely preventing any possible attack of the fibroin, even in the case of an error in the amount of composition incorporated with the bath, which enhances considerably the reliability of the treatment.

Our improved composition may also serve advantageously for the removal of greasing oils and of the impurities carried by all. fibres, whether animal, vegetable, mineral or synthetic.

The scouring of such fibres is executed in baths carrying about 2 gr. of the composition per litre of water. The baths are used at a temperature of 60 to 80 C. depending on the fibre. The scouring treatment should last from 20 to 30 minutes or thereabouts.

Our invention is obviously not limited to the embodiments and applications more particularly disclosed and it covers all the modifications falling within the scope of the accompanying claims.

What we claim is:

1. A composition for degumming natural silk fibers and for scouring textile fibers which consists essentially of sodium oleate, in combination with substantially an equal amount by weight of a mixture of a minor portion by weight of sodium hexametaphosphate and a major portion by Weight of an alkaline material selected from the group consisting of sodium carbonate, and alkaline materials having an alkalinity equivalent to that of sodium carbomate.

2. A composition according to claim 1 which consists essentially of by weight 50% of sodium oleate, 35% of the alkaline material and 15% of sodium hexametaphos- .phate.

3. In a method for simultaneously scouring and dyeing textile fibres, the step of treating the fibres in an aqueous bath containing about 5 to 6 parts by weight of the fibres to be treated of a composition consisting essentially of sodium oleate, in combination with substantially an equal amount by weight of a mixture of a minor portion by weight of sodium hexametaphosphate and a major portion by Weight of an alkaline material selected from the group consisting of sodium carbonate and alkaline materials having an alkalinity equivalent to that of sodium carbonate.

4. A method according to claim 3 wherein the treatment takes place over a period of 20 to 30 minutes in an aqueous bath maintained at to C. and containing 2 g./liter of said composition.

References Cited Marsh, J. T., An Introduction to Textile Bleaching, 1946, p. 384.

Bryant, A Foam Method for Degumming Raw Silk, Textile Research Journal October 1950, pp. 735-36.

The Degumming of Silk, Silk Journal & Rayon World, June 1946, pp. 34, 35, 36 and 38.

MAYER WEINBLATT, Primary Examiner US. Cl. X.R. 8--l9, 139 

